Anatomical basis for study of acetabular migration of the prosthetic cup used in arthroplasty of the hip: a new technique for measurement of migration.

A retrospective study was carried out on 96 partial hip prostheses. Results of this study led us to define new radiological criteria for evaluation of the anatomical position of the prosthetic cup in the acetabulum. A method of measurement of the migration of the prosthetic cup in the acetabulum is proposed based on the results of roentgenological and anatomical study. The anatomical landmarks, geometric constructions and methods of computation of such measurement are described. The application of this technique to radiological/anatomical study was found to be reliable and allowed the determination of prognostic factors indicative of poor acetabular tolerance of the prosthetic cup.